My first son had whooping cough. He was around 4-6 months old. His coughing episodes were followed by vomiting. He had 12 plus episodes a day. I remember being excited when he had only had 8 episodes that day and it was already 2-3 in the aftrnoon as that was an improvement. Make sure to get some pedialyte to use if he dehydrates or his electrolytes go out of wack. I mixed an ounce of pedialyte with an ounce of breastmilk when my son became unresponsive and fed with a syringe. He perked right up. I also strapped him upright to my chest with a sling and slept in a chair to help with his breathing. Other than that I took garlic, vitamin c, and other natural stuff. I cannot remember completely just what they were though. My son is now 9 years old so it has been a while. He went undiagnosed. The doctors didn't take me seriously until he was at the tail end of his illness. Kinda pointless then.